In a known method of the type described above, a sealing strip, having a width larger than the thickness of the pane, is fitted along one edge of the pane. The corresponding frame element is then pushed over the edge of the pane and carries the strip along so that it fits snugly on each side of the pane, forming a seal between each of the two webs and the pane. The remaining frame elements are pushed on to the pane in the same way, and the corner forming ends of the frame elements are interconnected to form a closed frame.
The width of the strip is generally such that the edges of the strip, after the frame element has been fitted, lie flush with those edges of the U-webs of the frame elements facing the centre of the pane. The strip may be made from an elastomeric material, or may consist of a paper tape coated with a highly viscous material such as bitumen. In the last mentioned case the supporting paper tape is removed, when the sealing material has been placed on the edge of the pane.
This method has the drawback that it is difficult to guide the sealing strip to lie flush with the edges of the U-webs in the finished frame, and it may be necessary after assembly of the frame, to cut off material which has been carried onto the pane, especially when using a bituminous sealing strip.